public class color {
    class Solution {
        public void swap(int[] nums,int i,int j){
            int t = nums[i];
            nums[i] = nums[j];
            nums[j] = t;
        }
        public void sortColors(int[] nums) {
            int left = -1,right=nums.length,i=0;
            while(i<right){
                if(nums[i] == 0){
                    swap(nums,++left,i++);
                }
                else if(nums[i] == 1) i++;
                else swap(nums,--right,i);
            }
        }
    }
}
